Method and apparatus for the display and recordation of signals

ABSTRACT

THE PRESENT INVENTION PROVIDES APPARATUS AND METHODS FOR SIGNAL DISPLAY AND RECORDATION BY EMPLOYING THE SIGNAL CARRYING THE INFORMATION TO BE DISPLAYED AS A MODULATING SIGNAL FOR A LIGHT-EMITTING SOURCE. THE SYSTEM OF THE PRESENT INVENTION PROVIDES FOR THE DISPOSITION OF THE LIGHT EMITTED RESPONSIVE TO THE SIGNAL AND APPLIED THERETO TO BE   SPATIALLY CORRELATED ON A DISPLAY SURFACE TO THE AREA OF EMANATION OF SUCH SIGNAL. THE PRESENT INVENTION CONTEMPLATES THE INITIATING SIGNAL TO BE AN ULTRASONIC SIGNAL.

May 29, 1913 G, BA M Re. 27,650

METHOD AND APPARATUS FOR THE DISPLAY AND RECORDATION OF SIGNALS OriginalFiled Oct. 5, 1968 4 Sheets-Sheet 1 I a E x 5 11 5L I 1 I 9 1 i z. g

2565/1 61? /3/JHPUFIEE I I 22 fawn/nae 224 r EE ZiX-EEE I 2- ll v Arxmvsoucsk INVENTOR. 7 6/4552? fill/M FIG. 2 m Hg G. BAUM May 29, 1973METHOD AND APPARATUS FOR THE DISPLAY AND RECORDATION OF SIGNALS 4Sheets-Sheet 2 Original Filed Oct. 3, 1968 TIME'Q 22 reuswrrm INVENTOR.625507 540M W t Jim FIGS 5. BAUM Re. 27,650

METHOD AND APPARATUS FOR THE DISPLAY AND RECORDATIDN 0F SIGNALS May 29,1973 4 Sheets-Sheet 5 Original Filed 001;. 5, 196B 2 main [I Z6 Z7M/muummw FIG. 7A

INVENTOR. 6/4859 840M Arman/0a May 29, 1973 BAUM Re. 27,650

METHOD AND APPARATUSFOR THE DISPLAY AND RECORDATION OF SIGNALS OriginalFiled Oct. 5, 1968 4 Sheets-Sheet 4 emf/v52 LZ AMI/IE2 I r22 2 61ram/r152 1 PfiIZIIE if v 135 INVENTOR.

BY W+1 A f am/1r:

United States Patent 27,650 METHOD AND APPARATUS FOR THE DISPLAY ANDRECORDATION 0F SIGNALS Gilbert Baum, 152 Brite Ave., Scarsdale, N.Y.10583 Original No. 3,543,229, dated Nov. 24, 1970, Ser. No. 764,795,Oct. 3, 1968. Application for reissue Apr. 5, 1971, Ser. No. 131,185

Int. Cl. G01s 9/66 US. Cl. 340-3 R 33 Claims Matter enclosed in heavybrackets II] appears in the original patent but forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

ABSTRACT OF THE DISCLOSURE The present invention provides apparatus andmethods for signal display and recordation by employing the signalcarrying the information to be displayed as a modulating signal for alight-emitting source. The system of the present invention provides forthe disposition of the light emitted responsive to the signal appliedthereto to be spatially correlated on a display surface to the area ofemanation of such signal. The present invention contemplates theinitiating signal to be an ultrasonic signal.

The present invention relates to methods and apparatus for the displayand recordation of signals, and more particularly to methods andapparatus for the display and recordation of ultrasonic signals.

The use of ultrasonography as a diagnostic tool has, in recent years,become more intensified. It has been found that an object capable ofreturning echoes can be measured through the amplitude of the returningecho signals of an ultrasonic pulse sent to such object. In terms ofdiagnosis of the human body ultrasonography has the capabilities ofproviding information that is only otherwise obtainable by surgicalvisualization of the tissues.

However, the full potential uses of ultrasonography have not as yet beenobtained, due to the rather complex instrumentation employed in thedisplay of the data obtained.

Simply stated, the general techniques presently employed include the useof a scanning device, which scans the area of interest and emits anultrasonic pulse at various intervals. The returning echoes from eachpulse are presented on a cathode ray tube. This technique requires theuse of position signal generators, such as resolvers, otentiometers,special amplifiers, deflection yokes and a cathode ray tube display andequipment for cathode ray tupe photography.

Not only is the equipment and circuitry requisite in a cathode raydisplay relatively expensive, the circuitry itself is relativelycomplex, this compounding the propabilities of malfunction andrelatively expensive replacement and/ or repair.

An additional problem in presentation has been that of a scan producingdata of an incomplete nature. Unless the energy reflected from thevarious interfaces of the object studied returns to the echo recipient,there are no signals displayed to represent such interface. With thevarying contours generally found within the human body, theprobabilities of such incomplete data being received is accentuated. Toovercome this problem, various compound scanning techniques have beendeveloped to sample a particular interface from various angles, thusassuring receipt of the echoes of interest, and further defining theechoes of interest.

According to the present invention, methods and apparatus are providedfor presentation and recordation of the data carried by the returningechoes. The present ICC invention eliminates the need for cathode raytube display and all associated position generating equipment andfurther, provides the mechanism for compound scanning techniques so thata complete picture such as would be comparable to the compound scanP.P.I. (plan position indicator) picture displayed on the cathode raytube is obtainable.

The data obtained through use of the apparatus of the present invention,may be directed immediately to a photosensitive surface for permanentrecordation with the data display being in the nature of an intensitymodulated display. Light and dark areas will be presented on the face ofthe photosensitive surface, the light and dark areas being directlycorrelated to the intensity of the re turning echo from the object ofstudy.

The present invention generally provides a transmitter, generally atransducer of a piezo-electric nature, for the emission of theultrasonic pulse to the object for study; an echo recipient, whichpreferably is the same piezoelectric transducer, which picks up thevarious returning echoes from the pulse; a light source which is adaptedto emit a modulatable beam, whose intensity is modulatable based uponthe input of electrical stimulus thereto; and means to present the lightas emitted on the photosensitive surface across the face of suchphotosensitive surface in a like manner and directly correlated to themanner by which the ultrasonic pulse is passing through the object forstudy and returning echoes.

While as hereinafter described, the present invention has significantvalue in the use of the study human tissue such as the eye, it willbecome readily apparent that the invention has uses in a plurality ofother fields for the recordation of ultrasonic signals.

Although such novel feature or features believed to be characteristic ofthe invention are pointed out in the claims, the invention and themanner in which it may be carried out may be further understood byreference to the description following in the accompanying drawings.

FIG. 1 is a top schematic view of a compound scan according to thepresent invention.

FIG. 2 is a diagrammatic view of an apparatus of the present invention.

FIG. 3 is a diagrammatic view of an alternate embodiment of the presentinvention.

FIG. 4 is a diagrammatic vew of a further embodiment of the presentinvention.

FIGS. 5-7 are alternative views [of] in diagrammatic form of furtherembodiments of the present invention.

FIG. 7A is a front elevation of the reflective surface of FIG. 7.

FIG. 8 is a diagrammatic view of the present invention providing bothrecordation and simultaneous viewmg.

FIG. 9 is a diagrammatic view of an alternate simultaneous viewing andrecording embodiment.

FIG. 10 is a diagrammatic view of an additional embodiment of thepresent invention.

Referring now to the figures in greater detail where like referencenumbers denote like parts in the various figures.

FIG. 1 is a top view which illustrates the component parts of thecompound scan. The transducer 1 is preferably a piezoelectric elementwhich is adapted to emit an ultrasonic pulse when actuated and receivethe returning echoes. The object for study, generally denoted by thenumeral 2 sends a plurality of echoes back to the transducer 1 inresponse to a single ultrasonic pulse. These echoes are indicative ofthe various interfaces in the object 2 and the amplitude of thereturning echoes differs with respect to the structural makeup of thevarious interfaces. Thus, an ultrasonic pulse emitted from thetransducer 1 would pass through, for example, the object 2 along thepath indicated as A-A in FIG. 1, with a plurality of echoes returning inresponse to such pulse originating from various depths along line A-A.The transducer 1 is pivotally mounted to that when actuated, it willsweep across the object 2, as indicated by sector B. The transduceremits ultrasonic signals and receives echoes therefrom along the variouspoints of the object 2 within the sector B. This is what is commonlyreferred to as a sector scan or as a simple scan.

In order to study the object along various vantage points, thetransducer travels along arc DD, with the center of rotation of the arcDD being a point C on the object 2. The are is on a plane parallel tothe sector scan.

It may of course be appreciated that the mechanical motion of thetransducer as it pivots and travels along DD is relatively slow and thata great multitude of emissions and echo receptions take place within asimple sector scan B. The various sector scans B shown in phantom alongarc DD are merely illustrative, it being readily apparent that a greateror lesser number of sector scans may be provided for the transducer asit passes along arc DD.

Upon completion of a single compound scan, the transducer may then bevertically disposed along a lower or higher plane and the compound scanrepeated. While the foregoing has dealt with simple and compound sectorscans, it is readily apparent that a simple and compound linear scan maybe accomplished in a like manner.

if desired, the echoes received by the transducer 1 could be displayedon a cathode ray display and then photographically recorded. The use ofa cathode ray tube would then require associated position signalgenerators such as resolvers and potentiometers, operational anddeflection amplifiers and high resolution cathode ray tube displays andphotography. This equipment is very expensive and is extremely delicateand complex. Furthermore cathode ray tubes possess limited dynamic rangeand introduce noise into the system.

The present invention eliminates the need for resolvers orpotentiometers, cathode ray tubes, amplifiers and deflection amplifiersand simplifies the photographic process. Thus, as illustrated in FlG. 2,the transducer 1 is mounted on a shaft 4 and pivotally rotated for itssimple scan motion by a motor 5. As shown in FIG. 2, the transducer 1and the object 2 are preferably within a coupling medium 6 such aswater, glycerine, or oil, so that the energy generated by the transducermay be transferred to the object 2 with little dissipation and loss. Thecoupling medium 6 is contained in the examining tank 7.

The shaft 4 for the transducer is preferably at right angles to thetransducer and passes through a lighttight enclosure 9. A light source 8is preferably mounted at the center of rotation of the shaft 4 andaligned with the transducer 1, so as to provide a l-to-l aligned pivotalmotion as between the light source 8 and the transducer 1. The lightoutput of the light source 8 will vary in proportion to the amplitude ofthe returning echoes of the object 2. While various light sources areadaptable for such purpose, so long as they are able to react with aspeed sufficient to modulate a light beam which varies in intensity indirect proportion to the intensity of the returning echo, and modulatesuch beam at a high rate of speed, light sources having an ability toemit an intense collimated beam have been found highly suitable. Thus,lasers are suitable and p-n (positive-negative) junction galliumarsenide injection diode employed for a pulse operation, is alsoemployable with suitable optics. Additionally, the narrow beam soemitted aids the presentation of the data in that there is a minimum oflight dispersion. It should be noted that lasers may be of moreimmediate usage in that recordation on the photosensitive surface 12 ashereinafter described requires a photosensitive film or crystal with theability to record at great speeds a rapidly projected light.

Since the light source 8, as shown in FIG. 2 is mounted on the shaft 4of the transducer 1, the light source follows the mechanical pivotedrotation of the transducer 1. T he light source 8 is thereforepositionally displaced to a 1-to-1 relationship with the transducer 1.

Since a single ultrasonic pulse emitted from the transducer 1 along asingle given position during scanning will result in a plurality ofechoes, means must be provided for the positional displacement of thevarying intensity light beam so that its position correlates with theposition of the interface emitting the echo. Thus, referring to the pathof a single pulse A-A of FIG. 1, echoes which return from interfacesindicated as E E E B are to be positioned along the photosensitivesurface 12 as they are emitted from the radial coordinate A--A.

As shown in FIG. 2, a reflective surface 11, adapted to either rotateand/or oscillate along its longitudinal axis, provides the writing"mechanism for the light beams 10. The light source will emit a beamwhose amplitude varies in proportion to the amplitude of the receivedechos of the transducer. These amplitude varying signal are emitted bythe transducer through an amplifier 13 and act to fire the modulatedlight source 8. Thus, if the mirror is oscillated or rotated at a speedcorrelated to the speed of the returning echoes from the object 2 thelight beam 10 will strike the reflective surface 11 at a degree ofrotation of the reflective surface 11 so that the displacement of thelight beam on the photosensitive surface 12 will be proportional to thespeed of the echos from the object. Thus, the beam emitted light strikesthe reflective surface 11 at various intervals along the oscillating orrotating path of the reflective surface 11. The light beams will then be"written as a line across the face of the photosensitive surface 12 withthe line made up of various graduations of dark and light areasdepending upon the intensity of the beam as it was emitted from thelight source 8.

The reflective surface 11 is driven, as shown in FIG. 2 by a synchronousmotor 14 which is pretimed relative to the transmitted pulse and thespeed of the ultrasonic pulse through the coupling medium and thetissue.

Thus, for example, the speed of sound through body tissue isapproximately 1,500 meters per second. lf, therefore, the reflectivesurface 11 were rotated at a speed suflicient to provide a lineartraversal of the light beam at the photosensitive surface 12 of 1,500meters per second, it would constantly write the received echo signalsat physical spacings accurately corresponding to the actual physicalspacings of the sound reflecting interfaces in the object 2. However,since the transducer 1 pulses intermittently, that is a transmittingpulse to send an ultrasonic signal and then an off cycle to receiveechoes, the speed of oscillation or rotation of the reflective surfaceis preferably halved. The rotation of the mirror is synchronous with thetransmitted pulse and if desired the rotation of the mirror can be usedto trigger" the pulse to the transducer.

While not shown in the drawing, the reflective surface 1] and itssynchronous motor ]4 are mounted upon a yoke which is attached to, andforms a part of, the shaft 4 so that the reflective surface 11 swingsabout the shaft 4 in its simple scan motion To provide the compoundscanning arc DD- of FIG. 1, the light tight enclosure 9 is mounted on amoveable plate 15 which has its center of rotation 16 at point on theobject 2. The plate 15 is driven by conventional means to pivot, such asby a motor 17. Thus the entire lighttight enclosure will pivot about anare indicated as DD in FIG. 1 and at the same time the shaft 4 ispivoting the transducer 1 to provide the sector scan indicated in FIG. 1as B.

The entire assembly including the compound scanning plate 15 and itsassociated drive motor is mounted on a vertical stepper 17a by whichscans at different vertical levels may be made. The action of thevertical stepper 17a may be automated and sequential or may be manuallycontrolled.

In lieu of the reflective surface 11 such as shown in FIG. 2, anelectrooptic may be employed. Referring then to FIG. 3 anelectrooptically induced change of the refractive index of a crystal 18as the emitted light beams from the light source 8 passes therethroughmay effect the writing" of the light beam across the photosensitivesurface 12.

As a result of their linear electrooptic response, low conductivity,high optical transparency and high optical quality, KDP crystals(tetragonal potassium dihydrogen phosphate) and the more sensitive KD*P(potassium dideuterium phosphate) crystals may be highly suitable. Thesecrystals have what is termed an optic axis" and upon application of anelectric field at right angles to the optic axis the KDP and KB?crystals experience a change of refractive index as the electric fieldvaries. They thus provide deflectors and modulators offering widedynamic ranges with the ability to follow rapid variations in appliedvoltages.

The electric field which will change the optic axis of the crystal 18 isinitiated by a generator 19 which in turn is triggered by the signaloutput of the timer 22. Thus the electric field generated through thecrystal varies in proportion to the signal generated by the generator 19and is directly correlated to the reception signals of the transducer 1.A saw tooth generator would be readily adaptable for this purpose.

The crystal 18 is supported upon a yoke (not shown) to swing with shaft4 in the simple scanning motion.

In lieu of a direct affixation of the light source 8 on the transducershaft 4, a reflective surface 20 may be mounted on the center ofrotation of the shaft 4, such as illustrated in FIG. 4 with the lightsource 8 so positioned as to emit its beam and have such emitted beamdirected, such as by a mirror 21 to the reflective surface 20 to thewriting reflective surface 11 and then to the photosensitive surface 12.

As described in connection with FIG. 2, the reflective surface 11 andthe synchronous motor 14 are mounted upon a yoke which is attached toand forms a part of the shaft 4.

It is appreciated that the rotational or oscillating movement of thereflective surface 11 must be timed to correlate with the transducer 1and a timing and transmitting mechanism indicated generally in allfigures as 22, 2221 may be provided for such purpose.

It should also be noted that various compound scans along differentlevels of the object 2 are readily obtainable by having the plate 15actuatable vertically, through the stepping mechanism 17a associatedtherewith, as hereinbefore described. Thus, at the completion of acompound scan the plate can he stepped up or down thus raising orlowering the lighttight enclosure 9, shaft 4 and transducer 1.

An alternate arrangement is illustrated in FIG. wherein the light source8 is fixedly mounted within the lighttight enclosure 9, the light source8 lying in a plane along the central axis of the transducer shaft 23.The transducer shaft 23 only traverses partway into the lighttightenclosure 9 and the motor 24 which actuates the transducer 1 for itssector scan motion is positioned along the shaft. At the upper end ofthe shaft 23 is mounted the reflective surface 25. The reflectivesurface 25 is adapted to be oscillated through use of an oscillatingmeans 26. The speed of oscillation is controlled in the manner similarto that heretofore discussed with respect to FIG. 2, that is through atimer and transmitter, the speed of oscillation being directlycorrelated to the speed of sound through the object 2 for study. Thereflective surface 25 while reciprocating in the directions indicated bythe arrow F is also being rotated on the shaft 23 so that it follows thesector scan of the transducer 1. For simplicity and clarity, thereciver-amplifier 13 is not shown in this figure, but it is understoodto be present.

As illustrated in FIG. 6 the need for an oscillating reflector surfacecan be eliminated and the electrooptic crystals 18, such as the KDP andKD*P crystals hereinbefore described may be substituted. The refractionof the light beams as they pass through the crystal 18 is controlled ina like manner to that hereinbefore described with respect to FIG. 3.

In order to avoid possible timing difficulties with the oscillating androtating reflective surfaces hercinbefore described due to possibleinertially effected time lapses during change of direction or otherwise,the reflective surface may be in the nature of a plurality of reflectivesurfaces having predetermined attitudes circumferentially disposed abouta flywheel. Thus as shown in FIGS. 7 and 7A the light source 8 ismounted on a plane spaced apart from but along the central axis of thetransducer shaft 29 with the transducer shaft 29 having mounted thereona rotatable wheel 27 having reflective surfaces 28 of varying attitudesdisposed about its circumference. The reflective surfaces 28 intersectthe light beam emitted from the light source 8 at a point along thecentral axis of the shaft 29. The speed of rotation of the wheel 27 asit is driven by its associated motor 30 is timed to the timing andtransmitting mechanism 22, 22a as hereinbefore described. Since thewheel 21 is directly afiixed to the shaft 29 by arm 31 the wheel 27 willpivot to follow the sector scan of the transducer 1. The speed of theflywheel may be used as a control, as a timer, or as a trigger for thetransmitted pulse.

As with other embodiments the lighttight enclosure is mounted on theplate 15 so as to effect the compound scan upon actuation of the motor17, if such compound scan is desired.

If it is desired to have simultaneous viewing as well as photography anarrangement such as illustrated in FIGS. 8 and 9 may be employed. Asshown in FIG. 8 a. eriscope-arrangement is presented whereby the writtenbeam as it is directed towards the photosensitive surface 12, forexample by an arrangement similar to that hereinbefore described withrespect to FIG. 7, is split by a beam splitter 32. The split portion ofthe beam not directed to the photosensitive surface 12 is directed to amirror or screen 33. Either a photochromic mirror or screen or aphosphorescent screen may be employed. A photochromic screen wouldabsorb the light and emit an image having a hue other than that of thefrequency of the beam which struck it. The emitted light would then bedirected towards a dichroic mirror 34 which would mask all undesiredcolors and the beam could then be viewed through an optical filter 3Semplaced on one of the sides of the lighttight enclosure 9. It may bedesirable to employ a light shield 36 between the light source 8 and thephotochromic screen 33 so that the screen would only react to the splitbeam directed towards it.

In lieu of the photochromic screen a phosphorescent screen may beemployed so as to provide a greater resolution to the split beam andgreater lifetime to the light projected to the screen.

In view of the writing speed of the light beam it may be desirable inany event to provide a phosphorescent screen to be read by thephotosensitive surface 12 such as shown in FIG. 9. This can readily beaccomplished by removing the beam splitter of FIG. 8 so that the lightis transmitted directly to the phosphorescent screen 37. The image onthe screen 37 is then simultaneously viewed and photographed. Viewingmay be through the optical filter 35 on the lightight enclosure 9 withthe phosphorescent screen enhancing the liftime of the beam so that itis more easily read and recorded on the photosensitive surface 12.

While all of the light sources hereinbefore described whether of thelight diode or laser variety are adaptable to be modulated so far as theintensity of the beam emitted based upon the imput transmitted to it bythe transducer 1, it is within the scope of the present invention toemploy lasers such as are presently in development in the art which maybe interally deflected and modulated so that the light beams emittedfrom the laser 39 will sweep across the photosensitive surface 12. Thus,as is illustrated in FIG. a laser 38 mounted at the center of rotationof the transducer shaft would follow the arc of the sector scan of thetransducer 1; the positional movement of the lighttight enclosure 9 tofollow the compound scan; and would write across the face of thephotosensitive surface and thus eliminate the need for the reflectivesurfaces or electrooptic crystals hereinbefore described.

The internal deflection within the laser 38 would be controlled throughthe timer 22 and transmitter 22a in a like manner as hereinbeforedescribed with respect to the reflective surfaces 11, 25, and 28.

It is readily apparent that various other drive means for the variousreflective surfaces may be provided.

While various reflecting, refracting and modulating means have beenillustrated, it is within the scope of the present invention to providefor magneto-optic modulation and deflection; electrooptic modulation aswell as deflection; and various other acousto-optic deflection andmodulation means. Thus, for example, various crystals when subjected toa magnetic field or electric current will modulate a light beam andvarious known variable reflectors, variable refractors, birefringentdeflectors and interference deflectors may be substituted as thedeflecting, retracting or modulating means in lieu of those illustratedherein.

Additionally, various types of photosensitive surfaces such as lightsensitive crystals may be employed for recordation purposes.

While the foregoing has dealt primarily with ultrasonics it isappreciated that this entire system with the substitution of a microwavetransmitter for the piezoelectric crystal and microwave receiver for thereceiving element can be used to generate a radar P.P. I. display.

The terms and expressions which are employed are used as terms ofdescription; it being recognized though that various modifications arepossible though, within the scope of the invention claimed.

Having thus described certain forms of the invention in some detail whatis claimed is:

1. An apparatus for the display of an ultrasonic signal comprising,ultrasonic pulse emission means adapted to emit an ultrasonic pulse toan object, said ultrasonic pulse emission means being movably mounted toscan a planar path along said object, an echo recipient adapted tofollow the path of said ultrasonic pulse emission means and operable toreceive from the object echoes of the ultrasonic pulses emitted by theultrasonic pulse emission means, a light directing member spaced apartfrom said ultrasonic pulse emission means adapted to travel along aplane parallel to said planar path, a substantially light tightenclosure, said light directing member being positioned within saidlighttight enclosure, and means to present said echoes in an intensitymodulated display positionally displaced in ratio to the point ofemanation of each said echo from said object including, a light sourceconnected to said echo recipient and operable in response to varyingecho intensity signals received from said echo recipient and adapted toemit a collimated beam having an intensity variable in proportion to theintensity of said echo intensity signals, said light source beingpositioned within said lighttight enclosure, each said beam being guidedby said light directing member; light beam display means; and light beamdisplacement means interposed between said light directing member andsaid light beam display means and adapted to alter the path of each ofsaid light beams to present said light beams across the face of saiddisplay means to give a two-dimensional display of said received echoes.

2. The apparatus as claimed in claim 1 wherein said display meansincludes a photosensitive surface.

3. The apparatus as claimed in claim 1 wherein said display meansincludes a phosphorescent screen.

4. The apparatus as claimed in claim 1 wherein said display meansincludes a photochromic mirror and dichromic screen.

5. The apparatus as claimed in claim 1 wherein said light beamdisplacement means includes a reflective surface moveable about an axisfixed with respect to said light directing member [a fixed axis] andadapted to present varying attitudes of reflection to said light beams,said reflective surface timed to travel at a speed in ratio to the speedof said signals through said object.

6. The apparatus as claimed in claim 1 wherein said reflective surfaceincludes a rotating mirror.

7. The apparatus as claimed in claim 1 wherein said reflective surfaceincludes an oscillating mirror.

8. The apparatus as claimed in claim 1 wherein said reflective surfaceincludes a plurality of mirrors having difl'ering attitudes disposedabout a rotating wheel.

9. The apparatus as claimed in claim 1, wherein said moveable reflectivesurface is in operative contact with and adapted to trigger means totransmit signals to said object.

10. The apparatus as claimed in claim 1 wherein said light beamdisplacement means includes an electrooptic adapted to refract the lightbeams passing therethrough and said apparatus further includes means totransmit an electric signal at a right angle to the optic axis of saidelectrooptic.

11. The apparatus as claimed in claim 10 wherein said electrooptic is apotassium dihydrogen phosphate crystal.

12. The apparatus as claimed in claim 10 wherein said electrooptic is apotassium dideuterium phosphate crystal.

13. The apparatus as claimed in claim 10 wherein said means to transmitsaid electric signal to said electrooptic includes a generator.

14. The apparatus as claimed in claim 1 wherein said ultrasonic pulseemission means, said echo recipient and said light directing member areconnected to a common shaft.

15. The apparatus as claimed in claim 1 wherein said ultrasonic pulseemission means and said echo recipient are piezoelectric elements.

16. The apparatus as claimed in claim 1 wherein said ultrasonic pulseemission means and said echo recipient include a single piezoelectricelement.

17. The apparatus as claimed in claim 1 wherein said light source issaid light directing member.

18. The apparatus as claimed in claim 17 wherein said light source is alaser.

19. The apparatus as claimed in claim 17 wherein said light source is alight diode.

20. The apparatus as claimed in claim 16 including, means adapted torotate said shaft.

21. The apparatus as claimed in claim 16 wherein said lighttightenclosure is movably mounted and adapted to rotate about an axis alignedat to a point on said object.

22. The apparatus as claimed in claim 16 including means to alter thevertical position of said lighttight enclosure.

23. A method of displaying ultrasonic signal scan pulse generated datacomprising the steps of transmitting an ultrasonic pulse to an object,receiving signals from said object responsive to said transmitted pulse,said recipient signals being the returning pulse echoes therefrom,converting each of said recipient pulse signals to an electric pulsesignal having an intensity which is proportional to the recipient pulsesignal, transmitting said electric pulse signal to a light source tocause said light source to emit a pulsed collimated light beam having anintensity variable in proportion to the intensity of said electric pulsesignal and directing each said emitted beam pulse along a display zone,each said beam pulse being further spatially correlated along anotheraxis relative to the area of emanation of the signal to which said beamis responsive to g e a two-dimensional display of said received echo.

24. The method as claimed in claim 23 wherein the step of directing eachemitted beam to a spatial correlation relative to the area of emanationof said signal includes the refracting of each said emitted beam bypassage of each said light beam through an electrooptic prior to theprojection of each said beam on said display zone.

25. The method as claimed in claim 23 wherein the step of directing eachemitted beam to a spacial correlation relative to the area of emanationof said signal includes the reflecting of each said beam from areflective surface, said reflective surface travelling about an axisfixed with respect to said light source [a fixed axis] to present avarying attitude of reflection for each said beam, said reflectivesurface timed to travel at a speed in direct ratio to the speed of saidtransmitted signal through said object.

26. The method as claimed in claim 25 wherein the trigger of thetransmitting of said signals to said object is actuated by saidreflective surface.

27. The method as claimed in claim 23 wherein said display zone is aphotosensitive surface.

28. The method as claimed in claim 23 wherein said display zone is aphosphorescent screen.

29. The method as claimed in claim 23 including the penultimate step ofdirecting said light beam to a photoehromic mirror and wherein saiddisplay zone is a dichroic screen.

30. The method as claimed in claim 23 further including the step ofrepeating said ultrasonic pulsing and echo reception along a transverseplane through said object.

31. The method as claimed in claim 23 further including the step oftransmitting said ultrasonic pulses from varying points equidistant froma point on said object.

32. The method as claimed in claim 23 further including the step ofrepeating said ultrasonic pulsing and echo reception along at least asecond transverse plane.

33. The method as claimed in claim 23 further including the step ofrepeating said ultrasonic pulsing and echo reception along at least asecond transverse plane through said object.

References Cited The following references, cited by the Examiner, are ofrecord in the patented file of this patent or the original patent.

OTHER REFERENCES Preston et a1.: Applied Physics Letters, vol. 10, No.5, Mar. 1, 1967, pp. -152.

RICHARD A. FARLEY, Primary Examiner US. Cl. X.R. 346-108

